Regular Expressions 101

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An explanation of your regex will be automatically generated as you type.
Detailed match information will be displayed here automatically.
  • All Tokens
  • Common Tokens
  • General Tokens
  • Anchors
  • Meta Sequences
  • Quantifiers
  • Group Constructs
  • Character Classes
  • Flags/Modifiers
  • Substitution
  • A single character of: a, b or c
    [abc]
  • A character except: a, b or c
    [^abc]
  • A character in the range: a-z
    [a-z]
  • A character not in the range: a-z
    [^a-z]
  • A character in the range: a-z or A-Z
    [a-zA-Z]
  • Any single character
    .
  • Alternate - match either a or b
    a|b
  • Any whitespace character
    \s
  • Any non-whitespace character
    \S
  • Any digit
    \d
  • Any non-digit
    \D
  • Any word character
    \w
  • Any non-word character
    \W
  • Non-capturing group
    (?:...)
  • Capturing group
    (...)
  • Zero or one of a
    a?
  • Zero or more of a
    a*
  • One or more of a
    a+
  • Exactly 3 of a
    a{3}
  • 3 or more of a
    a{3,}
  • Between 3 and 6 of a
    a{3,6}
  • Start of string
    ^
  • End of string
    $
  • A word boundary
    \b
  • Non-word boundary
    \B

Regular Expression
No Match

/
/
gm

Test String

Code Generator

Language

Generated Code

use strict; my $str = 'WBC 4.27-11.40 k/uL 3.64 (L) RBC 3.90-5.03 m/uL 4.30 Hemoglobin 10.6-13.4 g/dL 13.0 Hematocrit 32.2-39.8 % 36.1 MCV 74.4-87.6 fL 84.0 MCH 24.8-29.5 pG 30.2 (H) MCHC 31.8-34.9 g/dL 36.0 (H) RDW-CV 12.2-14.4 % 13.2 Platelet Count 150-400 k/uL 175 MPV 9.2-11.4 fL 8.6 (L) Neut% 28.6-74.5 % 43.1 Abs Neut (ANC) 1.63-7.87 k/uL 1.57 (L) Lymph% 15.5-57.8 % 43.7 Abs Lymph 0.97-4.28 k/uL 1.59 Mono% 4.2-12.3 % 9.3 Abs Mono 0.19-0.85 k/uL 0.34 Eosin% 0.0-4.7 % 3.6 Abs Eosin 0.00-0.52 k/uL 0.13 Baso% 0.0-0.7 % 0.3 Abs Baso 0.00-0.06 k/uL 0.01'; my $regex = qr/\d+-\d[\d.]*\s*\K\S+/mp; if ( $str =~ /$regex/g ) { print "Whole match is ${^MATCH} and its start/end positions can be obtained via \$-[0] and \$+[0]\n"; # print "Capture Group 1 is $1 and its start/end positions can be obtained via \$-[1] and \$+[1]\n"; # print "Capture Group 2 is $2 ... and so on\n"; } # ${^POSTMATCH} and ${^PREMATCH} are also available with the use of '/p' # Named capture groups can be called via $+{name}

Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Perl, please visit: http://perldoc.perl.org/perlre.html